Supporting immunomodulatory agent

ABSTRACT

The invention relates to an agent supporting the immunomodularity for the treatment of autoimmune diseases, said agent containing C 3 -C 8  carboxylic acids, their physiologically tolerable salts and/or esters with C 1 -C 8  alkyl alcohols, their use as supporting immunomodulators for autoimmune related diseases and immune-mediated chronic inflammatory diseases, as well as dietary supplements with immunomodulating effect containing these.

The invention relates to an agent supporting immunomodularity for the treatment of autoimmune diseases and immune-mediated chronic inflammatory diseases, said agent containing C₃-C₈ carboxylic acids, their physiologically tolerable salts and/or esters with C₁-C₈ alkyl alcohols.

While with autoimmune-related diseases the body's own structures are targeted as a result of a dysfunctional immune response, for example in the case of multiple sclerosis MS, immune-mediated chronic inflammatory diseases cause inflammation of various tissues, for instance of the intestines (Crohn's disease, Colitis ulcerosa), of the skin (psoriasis) or of the joints (spectrum of rheumatic diseases). Common to all these disease conditions is that as a consequence of the inflammation other types of diseases may occur with an above-average frequency such as overweight, high blood pressure, arteriosclerosis, cardiac infarction, and apoplexia.

Recent knowledge gained in the field of microbiomes have shown that nutrition, the intestinal microbiome, and the local cellular immune response are interconnected. Therefore, it is obvious that taking dietary measures can have an influence on the cellular immune response and thus on the process of autoimmune diseases as well as immune-mediated chronic inflammatory diseases.

An essential role in this context play regulatory T cells (Treg) as well as the diversity of the microbiome. Despite many open questions, in particular which components of the microbiome are actually responsible for a differentiated adaptive immune response in the intestinal region, a great amount of empiric information has been collected saying that individual types of bacteria and their bacterial metabolites exert a considerable influence on the systemic immune response in connection with diseases and autoimmunity and immune-mediated chronic inflammatory diseases, for example in case of type 1 diabetes and Crohn's disease.

It has further been found that the intestinal microbiome can be influenced by the type of nutrition consumed and is capable of adapting to the requirements to be met for a given kind of food. This means, an intestinal microbiota unfavorable for the immune status of a patient can be changed by taking suitable dietary measures aimed at improving the immune status of the patient.

The intestinal microbiome as well as the dietary habits, for example a high salt intake, have recently been identified as environmental influences on the pathogenesis of multiple sclerosis (MS) as prototype of an autoimmune-related disease of the central nervous system mediated by T cells. The influence of the intestinal microbiome on chronic inflammatory diseases of the intestines and type 1 diabetes has been mentioned before. Peculiarities of the intestinal microbiota have also been detected in patients suffering from type 2 diabetes.

Fatty acids have an especially great influence on the regulatory T cells and the intestinal microbiome. It has been found that long-chain fatty acids exert an inhibiting impact on both the regulatory T cells and on the intestinal microbiota. It came as a surprise to learn that short-chain fatty acids had a positive effect on the proliferation and thus amount of regulatory T cells found in the intestines as well as in the blood. This applies, in particular, to propion acid, butyric acid and their physiologically tolerable salts and esters. Moreover, it has been ascertained that the well-aimed administration of short-chain fatty acids with three to eight carbon atoms has a positive influence on the development and course of neuroimmunological diseases with neurodegenerative aspects, as for example MS.

Accordingly, the invention relates to an agent of the kind first mentioned above containing C₃-C₈ carboxylic acids, their physiologically tolerable salts and/or esters with C₁-C₈ alkyl alcohols.

The agent proposed by the present invention may be applied with immunomodulating effect as dietary supplement and also for the production of a medical agent accompanying the therapy of autoimmune related diseases and immune-mediated chronic inflammatory diseases as well as their deuteropathies.

Autoimmune related diseases in this sense are primarily those the development of which is associated with saliences in the intestinal microbiota and in the existing regulatory T cells. For example, these may be neurodegenerative diseases such as MS but also psoriasis, IBD, rheumatoid arthritis and the various types of diabetes.

The effectiveness of the inventive agent is restricted to short-chain carboxylic acids, i.e. those with no more than eight carbon atoms. In the event of longer chained carboxylic acids contrary effects are encountered since carboxylic acids with twelve or more carbon atoms usually exert a negative effect on the development and course of the disease.

Especially preferred are propion acid and butyric acid as well as their salts and esters.

Carboxylic acids shall be understood to be monocarboxylic acids preferably of straight-chain configuration. The monocarboxylic acids may also contain double bonds. However, preferred are straight-chained saturated carboxylic acids, in particular those with three or four carbon atoms.

As physiologically tolerable or acceptable salts the alkali and alkaline earth salts are primarily suited, and, moreover, salts of physiologically unobjectionable or essential heavy metals, for example zinc or iron. Of the alkali metals, sodium and potassium are especially preferred, as well as magnesium and calcium with respect to alkaline earth salts.

Of esters, preference is given to methyl and ethyl esters.

The carboxylic acids proposed by the invention and their esters and salts may be combined with fumaric acid esters and salts as well as with vitamin A and D, for example with dimethyl fumarate and salts of fumaric acid monomethyl ester.

Basically, the inventive agent may be provided in any marketable form. Preferred are capsules and tablets. Capsules are called for in the event liquid acids or esters are put to use. Acids in the form of fixed salt, for instance as sodium propionate or sodium butyrate, may also be compressed into tablets making use of customary tableting means.

As a rule, the capsules and tablets contain a unit dose of 0.2 to 5 g, in particular of 0.5 to 3 g.

According to the invention, the agents can be administered allowing for a daily intake of up to 10 g. However as a rule, one capsule or tablet of a maximum of 5 g per day will be sufficient.

Moreover, the invention also relates to the use of C₃-C₈ carboxylic acids, their physiologically tolerable salts and esters with C₁-C₈ alkyl alcohols as supporting immunomodulators for autoimmune related diseases. These carboxylic acids may as well be employed for the production of a medical substance intended to accompany the therapy of autoimmune diseases, and also a dietary supplement having an immunomodulating effect.

The inventive acids, in particular propion acid and butyric acid have an influence on the bowel physiology and the microbiome present there. In this way, they have an impact on the composition of the microbiome. The number of bacteria degrading propionate and butyrate increases significantly while at the same time the normal intestinal microbiota are affected only slightly. In contrast, long-chain carboxylic acids (lauric acid) cause the number of Provotellaceae and some families of Phylum Bacteroidetes in mice to reduce significantly.

Mice treated with propion acid showed changes of the microbiota accompanied with an increase of the number of regulatory T cells (CD4⁺ CD25⁺ Foxp3⁺ Treg). Gene expression profiling of signature cytokines has shown increased values with respect to TGFβ1, IL-10—generally anti-inflammable messengers—and Foxp3 in mice with experimental autoimmune encephalomyelitis (EAE) fed on propion acid.

Moreover, the aliphatic chain length of the carboxylic acids also affects the Th1/Th7-mediated autoimmunity as well as the regulatory response of Treg in an in vivo mouse model. Mice fed on a lauric acid enriched diet showed in the EAE model a significant reduction of TH1 and TH17 cells in the small bowel and at the same time an accumulation of Th1/Th17 in the central nervous system which leads to the conclusion that the control of the inflammatory cells has been transferred from the bowel to the brain/spinal marrow. On the other hand and under otherwise similar conditions, propion acid caused a significant increase of TGFβ1, IL-10, and Foxp3. Taken as a whole and in comparison with a control group, a change for the worse was determined after the onset of the induced disease in the model of the MS subjected to a diet comprising long-chain fatty acids, whereas in mice that were prophylactically given propion acid a significant improvement could be ascertained.

As a result, propion acid appears to be able to change, respectively normalize a compromised balance occurring between Treg and effector T cells (Th1/Th17). In particular MS patients show such a disturbed balance.

Moreover, the data obtained attest to the fact that the inventive carboxylic acids favorably influence the human fat hormone metabolism. In this context, by administering these acids the adiponectin concentration in the blood significantly increases statistically. In comparison, resistin behaves conversely. Under the influence of the short-chain carboxylic acids the serum leptin content increases as well. Leptin serves to inhibit the appetite and hunger signals and in this way plays an important role for the regulation of the fat metabolism in mammals and likewise in human beings.

Adiponectin is produced by fat cells. If these are empty, the production is increased. Obese people have a low adiponectin level causing the effectiveness of insulin to become weaker. A low level of adiponectin in conjunction with genetic factors results in a higher risk of contracting diabetes mellitus and at the same time causes vascular damage long before diabetes has been discovered. People having a high adiponectin level are protected against the development of diabetes.

Experimental Findings

Mice kept under standardized conditions were fed on a normal diet enriched with long-chain fatty acids (30.9% lauric acid) and additionally with 200 μl of propionate daily administered orally. The propionate was given either at the time of disease induction (DI) or at the onset of the disease (OD).

For the induction of EAE the mice were anesthetized and administered two subcutaneous injections of a 50 μl emulsion applied to the left and right tail basis and comprising a total of 200 μg MOG₃₅₋₅₅ and 200 μg Freund's adjuvant (CFA) with 4 mg/ml of M. tuberculosis. Pertussistoxin (200 mg/mouse) was given intraperitoneally on day 0 and 2 after the induction. The clinical assessment took place on a daily basis using a 5-point scale (SEM). The assessment was as follows:

0=normal

1=Tail paralysis impairing raising

2=Gait ataxia

3=Paraparesis of hind legs

4=Tetraparesis

5=Death

Mice showing SEM 4 or 5 were excluded.

The results are shown in the Figures.

FIG. 1 shows a listing of the mice population fed on a diet enriched with lauric acid in comparison to a control group. Onset of the disease occurred after approximately ten days and the disease reached its peak after seventeen days. With respect to SEM values the control group scored better than the group fed on the diet enriched with lauric acid.

FIG. 2 shows a diagram that compares the mice population fed with propion acid versus a control group. The propion acid was administered either on the day of immunization (DI) or on the day the symptoms occurred (OD). It was found that the group that was given propion acid on the day the disease occurred showed a significantly more favorable disease course than the control group.

The influence of the propion acid on the relative axonal density, the demyelination of the white substance, and the number of CD3+-cells can be seen from FIG. 3. In any case, through administration of propion acid a significant improvement of the condition is brought about in comparison to the control group.

FIG. 4 shows the influence of the administration of propion acid on the CD4⁺⁻ CD25⁺ Foxp3 cells expressed as a significant increase in comparison to the control group.

From FIG. 5 the influence of the lauric acid enriched diet on the CD4⁺ CD25⁺ Foxp3 cells can be seen in comparison to a control group. The administration of the long-chain fatty acids had caused a reduction of the T cells versus the comparison value. The percentage of reduction depends on the concentration of the long-chain fatty acids.

FIG. 6 shows the influence of the administration of sodium propionate on the adiponectin level based on the assessment of a study involving 10 patients. Column A shows the condition prior to the administration of sodium propionate, column B after administration of a daily dose of 1,000 mg, half of it given in the morning, the other half in the evening. Column C shows the adiponectin level 4 weeks after the administration had been terminated. Statistically, the adiponectin level increases significantly to 120 resp. 130% and the effect lasts longer than the administration duration. 

1. Agent supporting the immunomodularity for the treatment of autoimmune diseases containing one or more C₃-C₈ carboxylic acids, their physiologically tolerable salts and/or esters with C₁-C₈ alkyl alcohols.
 2. Agent according to claim 1, characterized in that the carboxylic acids are straight-chained saturated carboxylic acids.
 3. Agent according to claim 1, characterized in that the carboxylic acids are C₃ or C₄ carboxylic acids.
 4. Agent according to claim 1, characterized in that the physiologically tolerable salts are salts of sodium, potassium, magnesium, calcium, zinc and/or iron.
 5. Agent according to claim 1, characterized in that the agent contains sodium propionate.
 6. Agent according to claim 1, characterized in that the physiologically tolerable esters are methyl esters or ethyl esters.
 7. Agent according to claim 1 in capsule or tablet form.
 8. Agent according to claim 7, characterized in that the capsules or tablets contain a unit dose of between 0.2 and 5 g, in particular between 0.5 and 3 g of the carboxylic acids, their salts or esters.
 9. Use of C₃-C₈ carboxylic acids, their physiologically tolerable salts and esters with C₁-C₈ alkyl alcohols, defined per claim 1, as supporting immunomodulators for autoimmune related-diseases and immune mediated chronic inflammatory diseases.
 10. Dietary supplement with immunomodulating effect containing C₃-C₈ carboxylic acids, their physiologically tolerable salts or esters with C₁-C₈ alkyl alcohols, as defined in claim
 1. 11. Agent according to claim 2, characterized in that the carboxylic acids are C₃ or C₄ carboxylic acids.
 12. Agent according to claim 2, characterized in that the physiologically tolerable salts are salts of sodium, potassium, magnesium, calcium, zinc and/or iron.
 13. Agent according to claim 3, characterized in that the physiologically tolerable salts are salts of sodium, potassium, magnesium, calcium, zinc and/or iron.
 14. Agent according to claim 2, characterized in that the agent contains sodium propionate.
 15. Agent according to claim 3, characterized in that the agent contains sodium propionate.
 16. Agent according to claim 4, characterized in that the agent contains sodium propionate.
 17. Agent according to claim 5 in capsule or tablet form.
 18. Agent according to claim 17, characterized in that the capsules or tablets contain a unit dose of between 0.2 and 5 g, in particular between 0.5 and 3 g of the carboxylic acids, their salts or esters.
 19. Use of C₃-C₈ carboxylic acids, their physiologically tolerable salts and esters with C₁-C₈ alkyl alcohols, defined per claim 18, as supporting immunomodulators for autoimmune-related diseases and immune mediated chronic inflammatory diseases.
 20. Use of C₃-C₈ carboxylic acids, their physiologically tolerable salts and esters with C₁-C₈ alkyl alcohols, defined per claim 5, as supporting immunomodulators for autoimmune-related diseases and immune mediated chronic inflammatory diseases. 